Antioxidant and Anti-Obesity Potential

South African Journal of Botany 120 (2019) 104–111 Contents lists available at ScienceDirect South African Journal of Botany journal homepage: www.elsevier.com/locate/sajb Metabolite profiling and biological properties of aerial parts from Leopoldia comosa (L.) Parl.: Antioxidant and anti-obesity potential M. Marrelli a,F.Aranitib, G. Statti a, F. Conforti a,⁎ a Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, I-87036 Rende, CS, Italy b Department of AGRARIA, University “Mediterranea” of Reggio Calabria, I-89100 Reggio Calabria, Italy article info abstract Article history: Different anti-obesity drugs have proved unsuccessful due to their adverse effects. As a consequence, there is a Received 4 October 2017 growing interest in herbal remedies, with the aim to find new well-tolerated effective drugs. Leopoldia comosa Received in revised form 19 December 2017 (L.) Parl. grows in Central and Southern Europe, Northern Africa and Central and South-Western Asia, and the Accepted 6 January 2018 bulbs have been commonly used for food throughout history. In this study the effectiveness of L. comosa (L.) Available online 12 February 2018 Parl. leaves and inflorescences hydroalcoholic extracts and fractions was verified through the evaluation of pan- fi Keywords: creatic lipase inhibitory activity. The metabolite pro ling and the antioxidant activity were also investigated. fl – Antioxidant Chemical composition of L. comosa leaves and in orescences was assessed by means of GC MS and HPTLC anal- Chemical composition yses. The ethyl acetate fraction of leaves sample showed the best antioxidant activity, tested through DPPH and Leopoldia comosa β-carotene bleaching test. The effects on pancreatic lipase activity were assessed through the in vitro evaluation Lipase inhibition of the capacity to prevent p-nitrophenyl caprylate hydrolysis. Interestingly, leaves and inflorescences extracts and all their fractions were effective in inhibiting pancreatic lipase. The best anti-obesity potential was demonstrated by the n-hexane and the ethyl acetate fractions of leaves sample, with IC50 values of 0.369 ± 0.020 and 0.336 ± 0.007 mg/mL. The same fractions of the inflorescences hydroalcoholic extract were also effective, with IC50 values equal to 0.736 ± 0.045 and 0.780 ± 0.009 mg/mL. These results suggest that investigated samples could be a source of interesting compounds able to suppress dietary fat absorption. © 2018 SAAB. Published by Elsevier B.V. All rights reserved. 1. Introduction few new drugs have been introduced, and the only two available in Europe are naltrexone sustained release (SR)/bupropion SR and Different drugs, such as dinitrophenol, amphetamines and liraglutide, recently approved in both USA and Europe (Krentz et al., sibutramine, have been utilized against obesity in the last decades. How- 2016). ever, despite some promising results, all of them have been withdrawn Recently, novel natural molecules have been studied and have been because of their serious adverse effects (Marrelli et al., 2016a). For many proved to play a role as key regulators in metabolic and inflammatory years, orlistat ((S)-2-formylamino-4-methyl-pentanoic acid (S)-1- pathways related to obesity, such as irisin (Ferrante et al., 2016a), [[(2S,3S)-3-hexyl-4-oxo-2-oxetanyl]-methyl]-dodecyl ester) was the apelin-13 (Ferrante et al., 2016b), endomorphin-2 (Brunetti et al., only anti-obesity drug approved in Europe for long-term use. This mol- 2013), chemerin (Brunetti et al., 2014a), and omentin-1 (Brunetti ecule is a chemically synthesized hydrogenated derivative of lipstatin, a et al., 2014b). natural product of Streptomyces toxytricini. Orlistat acts through the inhi- Nowadays, with the aim to find well-tolerated natural effective bition of gastric and pancreatic lipases, key enzymes for the digestion of drugs, there is a great interest towards herbal remedies (Marrelli dietary triglycerides that form unbound fatty acids from dietary triglyc- et al., 2016a). Different classes of phytochemicals have been recently erides that are absorbed at the brush border of the small intestine. Al- demonstrated to be effective against obesity, such as some polyphenols though orlistat is a reversible inhibitor of these two enzymes, it is (Meydani and Hasan, 2010), terpenes (Birari and Bhutani, 2007; Singh considered essentially irreversible, from a clinical point of view, because et al., 2015) and phytosterols (Trigueros et al., 2013). Saponins are of the slow reversibility of the binding (Lucas and Kaplan-Machlis, other interesting secondary metabolites with potential anti-obesity ac- 2001). However, also orlistat causes some side effects, such as diarrhea, tivity, able to play a role in body weight control by different mechanisms fecal incontinence and dyspepsia (Marrelli et al., 2016a). From 1998, just of action (Marrelli et al., 2016a). Herbal products can inhibit lipid absorption, increase energy expen- ⁎ Corresponding author. diture, decrease pre-adipocyte differentiation and proliferation. Other E-mail address: fi[email protected] (F. Conforti). anti-obesity mechanisms are a decreased lipogenesis or an increased https://doi.org/10.1016/j.sajb.2018.01.006 0254-6299/© 2018 SAAB. Published by Elsevier B.V. All rights reserved. M. Marrelli et al. / South African Journal of Botany 120 (2019) 104–111 105 lipolysis (Hasani-Ranjbar et al., 2013). The potential health benefits of Table 1 different plant extracts have been demonstrated in the last few years Percentage yield of L. comosa (L.) Parl. leaves and inflorescences hydroalcoholic extracts and fractions. (Mocan et al., 2016, 2017; Savran et al., 2016) and some natural anti- obesity agents from medicinal plants have reached clinical trials Sample Fraction Yield %a (Marrelli et al., 2016a; Zengin et al., 2017). However, natural com- Leaves Raw extract 4.1 pounds have not been yet fully investigated and, potentially, new effec- n-Hexane 0.07 tive molecules could be discovered. CH2Cl2 0.17 As a continuation of our ongoing studies aimed to find effective anti- AcOEt 0.17 Inflorescences Raw extract 5.3 obesity botanicals (Conforti et al., 2012a; Marrelli et al., 2013, 2014, n-Hexane 0.07 2016b, 2016c), here we report the potential anti-obesity activity of CH2Cl2 0.05 Leopoldia comosa (L.) Parl. aerial parts. AcOEt 0.15 Leopoldia comosa (L.) Parl. (syn. Muscari comosum (L.) Miller, a % of extraction for 500 g of dried material. Data from one representative extraction. Liliaceae) grows in Central and Southern Europe, Northern Africa and Central and South-Western Asia. This species is present in the whole of Italy. The most common Italian popular name “cipollaccio” is due to 2.3. Total phenolic and flavonoid content estimation similarity of the bulb shape and taste to garlic, onion and leek. The bulb of L. comosa (L.) Parl. has been commonly used for food throughout The amount of total phenolics of L. comosa leaves and inflorescences history and, actually, it is commonly used as food in some rural commu- hydroalcoholic extracts was determined by the Folin-Ciocalteau nities in the south of Campania, in Apulia, in Basilicata and in Northern method (Araniti et al., 2014). Samples were mixed with distilled Calabria, where this species is just occasionally cultivated while the har- water, sodium carbonate solution and Folin-Ciocalteau reagent. After vesting of wild specimens is widespread. L. comosa bulbs are usually 2 h the absorbance of the blue color produced was measured at consumed fried in olive oil, occasionally mixed with cheese and eggs, 765 nm. Chlorogenic acid was used as standard and total phenolic con- boiled and served with a sweet and sour sauce, or pickled. Sometimes tent was expressed in mg per g of crude extract. the bulbs, after boiling with water and vinegar, are preserved with Flavonoid content was instead determined using a method based on olive oil (Casoria et al., 1999). The antioxidant activity of the bulbs of the formation of a flavonoid-aluminum complex (Marrelli et al., 2015). this plant has been already investigated (Pieroni et al., 2002). We also Each sample (2 mg/mL in EtOH 80%) was mixed with 2% AlCl3 in EtOH recently reported the phytochemical composition of this plant part, to- and absorbance was measured at 430 nm after 15 min. Results were gether with its interesting potential health benefits in the treatment of expressed as quercetin equivalents in mg per g of crude extract. obesity (Marrelli et al., 2017). Both quantifications were conducted in triplicate. Here we want to report the phytochemical content and the biological activity of L comosa aerial parts. Leaves and inflorescences were test- 2.4. HPTLC analysis ed for their ability to inhibit pancreatic lipase in vitro. Lipase inhibition is one of the most important strategies used by pharmaceutical industries For the analysis of polar compounds, the AcOEt fractions of L. comosa to decrease fat absorption after its ingestion (Marrelli et al., 2016a). The extracts were investigated by means of High Performance Thin Layer antioxidant activity and the phytochemical content of both leaves and Chromatography (HPTLC). One microliter of the two samples inflorescences were investigated as well. To the best of our knowledge, (50 mg/mL in methanol) was applied in triplicate on silica gel 60 glass this is the first study concerning the chemical composition and the bio- plates 20 cm × 10 cm (VWR International s.r.l., Milan, Italy) using logical properties of leaves and inflorescences of this plant species. Linomat 5 automated TLC applicator (CAMAG, Muttenz, Switzerland) according to the same operating conditions previously described 2. Materials and methods (Menichini et al., 2013). The presence of different flavonoids, such as quercetin, quercitrin, catechin, kaempferol, naringin and rutin was 2.1. Chemicals assessed using the corresponding standard at a concentration of 3 mg/mL. Plates were developed using the mobile phase AcOEt/ Ethanol, methanol, n-hexane, dichloromethane and ethyl acetate of CH Cl /CH COOH/HCOOH/H O (100:25:10:10:11; v/v/v/v/v) and suc- analytical grade were purchased from VWR International s.r.l.

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